Magnetic tape data storage media provides a means for storing large amounts of data, and typically comprises an elongate media with plurality of data tracks that extend longitudinally along the tape. A tape head is employed for reading and/or writing data on the data tracks, and is typically shared between various parallel sets of data tracks in one or more data bands. The tape head is moved between sets of tracks and data bands in the lateral direction of the tape. The tape head typically comprises a number of separate elements which read and/or write data with respect to a set of tracks comprising number of parallel data tracks, and is associated with separate servo sensors, which are laterally offset to either side from the read and/or write elements.
The magnetic tape media is typically very thin in order to accommodate a greater length of tape on a cartridge reel, and thereby store a large amount of data. Additionally, the data tracks are each narrow and are spread across the tape to maximize the amount of data stored in a given length of magnetic tape media.
The magnetic tape media typically provides servo tracks between bands of parallel data tracks and at the outside edges of the tape, so that a servo system can access a set of data tracks within a band of tracks intermediate two servo tracks, and can track the set of data tracks despite lateral movements of the magnetic tape.
After repeated usage of the very thin media, the edge of tape can become weakened and slightly stressed. When this happens the edge of the tape can become slightly stretched or worn, and may affect the readability of the servo and data tracks near the edge. A write operation may require that both the top and bottom servo signals be valid, and if the readability of the servo track at an edge is adversely affected to the extent that error recovery procedures do not allow the write operation to continue, the write operation may be aborted as having a permanent write error.